1. Field of the Invention
The present invention relates to a method of producing a metal complex-supporting mesoporous material, a metal complex-supporting mesoporous material, and a method of producing a mesoporous material supporting metal-containing nanoparticles using the metal complex-supporting mesoporous material.
2. Related Art
In recent years, metal nanoparticles or nanoparticles of metal-containing compounds have attracted attention as basic materials for use in medical drugs, electronically functional materials, environmentally compatible materials and the like. Metal-containing nanoparticles are fine particles having a diameter of typically no greater than 10 nm, and they are not only useful per se as medical drugs, electronic function materials, environmentally compatible materials and the like, but also superior in activities as a catalyst for synthesizing the same. Such characteristic features result from a quantum effect due to the nanoparticles being fine particles having a diameter of no greater than 10 nm, and a greater active surface area accompanied by being fine particles. However, preparation of metal-containing nanoparticles having a diameter of no greater than 10 nm is difficult, in general, since an agglutinative action among the particles increases along with the extent of micronization.
Under such circumstances, as methods for producing metal-containing nanoparticles, methods in which a dendrimer compound is used as a template have been proposed (see, for example, Patent Document 1). Dendrimer compounds that include in the backbone a nitrogen atom, etc., having an unpaired electron pair are capable of forming a complex with a Lewis acid, and can incorporate a variety of molecules and atoms within their molecules.
For example, in a known method, a complex composed of a dendrimer compound called TPM-G4 and PtCl4 is reduced with sodium borohydride in a solution to prepare a dendrimer compound encapsulating Pt nanoparticles, and the dendrimer compound encapsulating Pt nanoparticles is then supported in pores of mesoporous carbon (see Non-Patent Document 1). The dendrimer compound called
TPM-G4 is described in Non-Patent Document 2.
If the method described in Non-Patent Document 1 is applied to a method of producing metal-containing nanoparticles using a dendrimer compound as a template, mesoporous carbon supporting Pt nanoparticles can be prepared by removing the dendrimer compound from mesoporous carbon supporting the dendrimer compound encapsulating Pt nanoparticles.
[Patent Document 1] Japanese Unexamined Patent Application (Translation of PCT Application), Publication No. 2001-508484
[Non-Patent Document 1] Takane Imaoka, Yushi Hongo, Wang Jae Chun, and Kimihisa Yamamoto, “Stabilization of catalyst by supporting sub-nano platinum cluster encapsulated in dendrimer”, The 110th Catalyst Forum A Proceeding, Sep. 14, 2012, p. 470
[Non-Patent Document 2] K. Yamamoto, T. Imaoka, W. Chun, O. Enoki, H. Katoh, M. Takenaga, and A. Sonoi, Nature Chem., 1, 397, 2009